Final answer:
A hematocrit test measures the percentages of RBCs, WBCs, and platelets in blood, with the hematocrit value differing by gender. A differential WBC count classifies and counts various types of leukocytes in a blood smear. Together, these tests help diagnose conditions like polycythemia and assess the overall state of the patient's blood health.
Step-by-step explanation:
Hematocrit and Differential WBC Count
A hematocrit is a blood test that measures the percentage of red blood cells (RBCs), white blood cells (WBCs), and platelets in a unit of blood. The process involves spinning a blood sample in a centrifuge to separate these formed elements based on their weight. After centrifugation, RBCs, or erythrocytes, settle at the bottom, followed by a pale layer known as the buffy coat (composed of leukocytes and thrombocytes). The top layer is the plasma. An elevated hematocrit can indicate a condition such as polycythemia, which might be a result of dehydration or bone marrow diseases like polycythemia vera.
A differential white blood cell (WBC) count involves creating a blood smear and staining it to identify and count the various types of leukocytes. This helps in diagnosing and monitoring different diseases, such as infections or blood disorders, by comparing the counts with normal reference values.
The packed cell volume (PCV) is the volume of erythrocytes after centrifugation and is represented as a percentage of the total blood volume. The hematocrit values differ by gender and other factors, with women having a lower normal range compared to men.